{"id":59114,"date":"2023-11-28T15:01:44","date_gmt":"2023-11-28T07:01:44","guid":{"rendered":"https:\/\/www.hongkiat.com\/blog\/?p=59114"},"modified":"2023-11-26T18:19:32","modified_gmt":"2023-11-26T10:19:32","slug":"linux-command-tail","status":"publish","type":"post","link":"https:\/\/www.hongkiat.com\/blog\/linux-command-tail\/","title":{"rendered":"How to Use the Tail Command in Linux"},"content":{"rendered":"

The tail<\/code> command stands for \u201ctail of the file,\u201d and as the name suggests, it\u2019s primarily used to view the last part of files. Whether you\u2019re monitoring log files or tracking real-time data changes, tail<\/code> is your go-to utility.<\/p>\n

The command is often used in conjunction with other Linux commands like grep<\/a><\/code> for searching, awk<\/code> for text processing, and |<\/code> (pipe) for chaining multiple commands together. For example, you might use tail -f \/var\/log\/syslog | grep \"error\"<\/code> to monitor system logs for errors in real-time.<\/p>\n

General syntax for tail<\/code> command:<\/p>\n

\r\n$ tail [OPTION...] [FILE...]\r\n<\/pre>\n
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1. Display the exact number of lines<\/h3>\n
tail -n [number] [file]<\/pre>\n
Using this option allows you to get the tail<\/code> command to produce output that will display a certain number of lines in a file.<\/p>\n
Example:<\/strong><\/p>\n
Suppose you have a text file named example.txt<\/code> with the following content:<\/p>\n
Line 1: This is the first line.\r\nLine 2: This is the second line.\r\nLine 3: This is the third line.\r\nLine 4: This is the fourth line.\r\nLine 5: This is the fifth line.\r\nLine 6: This is the sixth line.\r\nLine 7: This is the seventh line.\r\nLine 8: This is the eighth line.\r\nLine 9: This is the ninth line.\r\nLine 10: This is the tenth line.<\/pre>\n
If you want to display the last 3 lines of this file, you would use the following command:<\/p>\n
tail -n 3 example.txt<\/pre>\n
This will show you the last 3 lines of the example.txt<\/code> file.<\/p>\n
Line 8: This is the eighth line.\r\nLine 9: This is the ninth line.\r\nLine 10: This is the tenth line.<\/pre>\n
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2. Display lines starting from a specific line number<\/h3>\n
tail +[number] [file]<\/pre>\n
The command with the +<\/code> sign outputs data starting from the specified line number.<\/p>\n
Example:<\/strong><\/p>\n
Let\u2019s say you have a text file named example.txt<\/code> with the following content:<\/p>\n
Line 1: This is the first line.\r\nLine 2: This is the second line.\r\nLine 3: This is the third line.\r\nLine 4: This is the fourth line.\r\nLine 5: This is the fifth line.\r\nLine 6: This is the sixth line.\r\nLine 7: This is the seventh line.\r\nLine 8: This is the eighth line.\r\nLine 9: This is the ninth line.\r\nLine 10: This is the tenth line.<\/pre>\n
If you want to display the content starting from line 5 to the end of the file, you can use the following command:<\/p>\n
tail +5 example.txt<\/pre>\n
The output will be:<\/p>\n
Line 5: This is the fifth line.\r\nLine 6: This is the sixth line.\r\nLine 7: This is the seventh line.\r\nLine 8: This is the eighth line.\r\nLine 9: This is the ninth line.\r\nLine 10: This is the tenth line.<\/pre>\n
\n
3. Display multiple files<\/h3>\n
tail [file1] [file2]<\/pre>\n
Use this command to display the data of multiple files at the same time.<\/p>\n
Example 1: Viewing the Last 10 Lines of a Single File<\/strong><\/p>\n
Let\u2019s say you have a file named example.txt<\/code> with the following content:<\/p>\n
Line 1: Hello\r\nLine 2: World\r\nLine 3: This\r\nLine 4: is\r\nLine 5: a\r\nLine 6: sample\r\nLine 7: text\r\nLine 8: file\r\nLine 9: for\r\nLine 10: demonstration\r\nLine 11: purposes\r\nLine 12: only<\/pre>\n
Running the command:<\/p>\n
tail example.txt<\/pre>\n
Will output:<\/p>\n
Line 3: This\r\nLine 4: is\r\nLine 5: a\r\nLine 6: sample\r\nLine 7: text\r\nLine 8: file\r\nLine 9: for\r\nLine 10: demonstration\r\nLine 11: purposes\r\nLine 12: only<\/pre>\n
Example 2: Viewing the Last 10 Lines of Multiple Files<\/strong><\/p>\n
Suppose you have another file named example2.txt<\/code> with the following content:<\/p>\n
Line 1: Another\r\nLine 2: Example\r\nLine 3: File<\/pre>\n
You can view the last 10 lines of both example.txt<\/code> and example2.txt<\/code> by running:<\/p>\n
tail example.txt example2.txt<\/pre>\n
This will output:<\/p>\n
==> example.txt <==\r\nLine 3: This\r\nLine 4: is\r\nLine 5: a\r\nLine 6: sample\r\nLine 7: text\r\nLine 8: file\r\nLine 9: for\r\nLine 10: demonstration\r\nLine 11: purposes\r\nLine 12: only\r\n\r\n==> example2.txt <==\r\nLine 1: Another\r\nLine 2: Example\r\nLine 3: File<\/pre>\n
The ==><\/code> <==<\/code> notation is used to separate the output from different files.<\/p>\n
\n
4. Output a certain number of bytes<\/h3>\n
tail -c [bytes] [file]<\/pre>\n
To display a specific number of bytes in a text file, use the -c<\/code> option.<\/p>\n
Example:<\/strong><\/p>\n
Let's say we have a file named sample.txt<\/code> with the following content:<\/p>\n
This is the first line.\r\nThis is the second line.\r\nThis is the third line.\r\nThis is the fourth line.\r\nThis is the fifth line.<\/pre>\n
If we want to display the last 20 bytes of this file, we would use the following command:<\/p>\n
tail -c 20 sample.txt<\/pre>\n
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5. Use multiple commands at once<\/h3>\n
tail [file] | [other_command]<\/pre>\n
Use the tail<\/code> command with pipes |<\/code> to use it in conjunction with another command.<\/p>\n
Example: Using tail<\/code> with grep<\/code><\/strong><\/p>\n
Let's say you have a log file called server.log<\/code> and you want to check the last 10 lines for any occurrences of the word \"error<\/code>\".<\/p>\n
tail server.log | grep 'error'<\/pre>\n
Here's what happens:<\/p>\n